SUS: How to Easily Grade Your Site’s Usability
Jens O. Meiert, November 27, 2009 / March 5, 2010.
This entry is filed under Usability.
The System Usability Scale (SUS) is a Likert scale-based questionnaire to grade the usability of systems. It got created back in the 80s by John Brooke. SUS questionnaire results are used to calculate a score between 0 and 100, with 100 indicating “best” usability. Since websites can be considered “systems,” SUS can also be used to grade websites.
Here’s how you can easily set up, use, and benefit from SUS. Grab the Website Usability Scale spreadsheet (we could actually dub SUS “WUS” in this context), take a copy using your Google Account, and use the associated form to ask users to answer a few questions.
This was brief. Here’s the more comprehensive how-to:
- Log in to your Google Account (the questionnaire templates are based on Google Docs).
- Open your preferred SUS template – either take the customized Website Usability Scale template, which talks about “websites,” not “systems,” or the original System Usability Scale template.
- In the top left, select “File”.
- Then, choose “Make a copy…”.
- Keep or change the name of the copy.
- Remove the first line in the spreadsheet which only contains dummy data:
- Right-click on the row number, “2”, which should select the whole row and also display a context menu.
- Select “Delete row”.
- Then, in the file menu at the top, go to “Form (0)”.
- Choose “Go to live form”.
- Voilà … you should now see the form you could ask your users to fill out; send them the URL, or just link the survey form from your site.
- You’ll see the results appear in your SUS spreadsheet copy; on “Sheet2”, the spreadsheet automatically calculates the SUS score. As noted before, the closer the number gets to 100, the better.
Don’t hesitate to ping me in case there are any issues.
Please note that SUS (or WUS) is not a substitute for user testing. It is more of a low cost method to evaluate usability, and to put a number on it. That it doesn’t get used very often, considering its age, is … interesting, but exactly the motivation for me to point to SUS again and make it easier to implement.
Whether or not SUS can be used as a standard evaluation tool for websites, however, stands and falls with its adoption—your tests—as well as more testing and feedback from usability professionals. I have some experience when it comes to usability research, testing, and evaluation, but my core domain is still something else. With this as the closing remark, just try SUS and share your findings and comments.
If you’ve got a minute, please take a quick survey rating meiert.com.
Update (March 4, 2010)
Luis Guilherme created a Portuguese spreadsheet template for SUS (thanks!).
Enjoy the most popular posts, possibly including:
On December 1, 2009, 15:54 CET, website laten maken said:
This sounds quite interesting. I never heard of this before, but I will definitely try and read more about this!
Filled in the rating for your site
On December 1, 2009, 23:20 CET, Dave said:
Very cool template. I’m not currently able to survey my users in this way, but the SUS/WUS questions are good food for thought about whether my site is meeting their needs.
On December 6, 2009, 18:39 CET, Mike Johnson said:
This is awesome. Thanks for posting. Looking forward to using this.